While many who grow long in tooth and gray of head look forward to moving to the Sunbelt and filling hours with shuffleboard and bingo, Eddie Perlmutter, retired from the Boston PD and relocated to Boca Raton, occupies his time rounding up hate-crime-committing Aryan thugs whom the bungling local force, unused to actual bad guys, fail to track down. Dubbed the Boca Knight in the first book in the series (Boca Knights, 2009), one-man-vigilante Eddie has now added random acts of altruism to his résumé (that and a lover half his age). He fills potholes left untended by a city-county jurisdiction squabble, busts cybercriminals and then finds them jobs, and even shows compassion for the offspring of an Aryan nudnik. His real challenge, though, is to find out what happened to an aging gay couple who went suddenly missing. This novel is long on clever dialogue and character development. Mystery readers of all stripes will like what they find here.